The removal of sticky, oily or liquid aerosol particulate matter from entrainment in exhaust gas streams in a frequently encountered problem. One method and apparatus that has been successful in removing such particulate matter is disclosed in U.S. Pat. No. 3,745,748. This patent discloses a rotating perforated drum around which a strip of filter media is fed. As the strip of filter media rotates with the drum, the gas stream with the particulate matter therein is drawn through the filter media to separate the particulate matter from entrainment with the gas stream. As the removed particulate matter clogs the filter media around the drum to a prescribed level, the clogged filter media is fed away from the drum. While this rotating drum filtration device has performed satisfactorily, the initial investment cost necessitated by the accessory equipment required to operate such an air filtration device has limited its use to large volume flow rates, usually above 9,000 acfm, in the gas streams in which the particular matter is entrained. Therefore, there has developed a need for an air filtration device which uses a filter media similar to that of the above mentioned patent but which can economically operate in small and medium volume flow rates in the gas streams in which the particulate matter is entrained.